Why would anyone max out their TSP?

I am maxing out my Roth IRA, Roth TSP, and investing in real estate. My goal is to plant a seed today so that my kids can rest in its shade when the time comes. My hope for them is to continue the cycle.

I'm an E5 and 2 years into my military career.

My aim for this discussion is to learn from others who are more experienced from me - but even more than that, I hope I can use my experience to council others who want to do the same. AMA.